(19)

(11)

EP 1 023 819 A2

(12)

(88) Date of publication A3: 22.10.1999 (43) Date of publication: 02.08.2000 Bulletin 2000/31 (21) Application number: 98953418.5 (22) Date of filing: 13.10.1998

(51) International Patent Classification (IPC)7: H05H 1/00 (86) International application number: PCT/US9821/534 (87) International publication number: WO 9920/087 (22.04.1999 Gazette 1999/16)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 14.10.1997 US 61941 P (71) Applicant: ADVANCED ENERGY INDUSTRIES, INC. Fort Collins, CO 80525 (US)	(72) Inventors: DRUMMOND, Geoffrey, D. Fort Collins, CO 80526 (US) MCDONOUGH, George Loveland, CO 80537 (US) SCHOLL, Richard, A. Fort Collins, CO 80526 (US) KERR, Tim Fort Collins, CO 80526 (US) HARPOLD, John, G. Bellvue, CO 80512 (US) (74) Representative: Kador & Partner  Corneliusstrasse 15 80469 München 80469 München (DE)